Why Lester is More

Jon Lester is a strange pitcher. He's strange in having pitched more innings against the Mets (5) than the Yankees (3.2). Strange in how he will absolutely dominate one batter and give up a 4-pitch walk to the next. Lester even destroys the myth that lefties can't pitch well at Fenway: his home ERA is 2.54, versus a road ERA of 4.71.

Perhaps the most remarkable thing about him is how much better Lester has been this year, as evidenced by his victory over the Orioles last night. Here are some of his stats:

In the context of his two previous years, two things stand out now: a lower WHIP (walks + hits per inning pitched) and more innings pitched in each start. Lester's WHIP has trended downward for the past two years; when he debuted in 2006 it was 1.648, last year it fell to 1.460, and now it's 1.35. Moreover, not only has Lester eclipsed his previous season high for innings pitched in the majors (81.1 in 2006), he's pitching deeper into games. His average is just under 6 innings per start; the last two years he averaged around 5.5 innings* before being lifted.

Basically, Lester is pitching more efficiently, and he's having success. From observation, he seems much more confident on the mound, more composed than in previous years. But this in itself is not enough to account for all of his improvement.

Interestingly, Lester's success is not the result of more strikeouts. His K / 9 is 5.74, a career low. His Ks / 9 in 2006 and 2007 were significantly higher, at 6.63 and 7.14 respectively.

Rather than overpowering batters, Lester is getting more ground outs; he has a ground-ball to fly-ball ratio of 1.45, versus 0.77 last year and 1.03 the year before. For comparison, sinkerballer Justin Masterson's GB/FB ratio is 1.52. With more groundballs come fewer opposing home runs, and more double plays. Lester has allowed only two homers (vs. 5 in '06), while inducing 12 double plays (only 8 in '06). A final reason for Lester's success is that he's giving up fewer walks: only 3.73 per 9 innings, a big improvement over '06 (4.76) and '07 (4.43).

If Lester can keep the ball on the ground and avoid walking people, he'll have a great year. With this strong start, he is poised to become a solid #2 starter - someone who will provide the team with high quality innings.